Arrangements are known for reading physical characteristics such as indentations or raised projections on one or more generally flat sides of a key, utilizing reading pins, and transmitting this reading, via electric or electronic means, to carry out a function. Such functions may include for example identifying the key holder, permitting access to a door or other secure area, or conveying the information to a key making machine to manufacture a duplicate of that key. Such an arrangement is shown in commonly owned U.S. Pat. No. 4,283,859, the subject matter of which is incorporated by reference herein.
In the arrangement shown in said patent, the physical characteristics on the side of the key are read by pins which, acting through mechanical multiplying means, cover or uncover light paths which in turn deactivate or activate photodetectors. These in turn relay the relevant information in connection with the function to ultimately be performed.
While this prior arrangement has proved highly successful, it has been found that in certain applications of the invention, spacial requirements are so restricted that there is insufficient room for the prior arrangement. In such cases, a need exists for improvements which will allow further miniaturization of the key reader.